It's estimated that as many as 3,000 wild pigs are on the loose in Michigan. Nationwide, they cause more than $1.8 billion in damage to farms each year. So recently, the state's Department of Natural Resources put Russian boar on the state's invasive species list.

Mute swans are flourishing in Michigan. The state’s Department of Natural Resources estimates their population almost tripled from 5,700 to more than 15,000 between 2000 and 2010. We've previously reported the DNR says mute swans eat a huge amount of vegetation in lakes. They can push out native birds, such as the trumpeter swan, and officials say mute swans can snap and charge at people.

To keep the population under control, the DNR is killing the birds and destroying their nests.

The Humane Society of the United States and the Michigan Save Our Swans Committee argue the DNR’s methods are inhumane.

Researchers are sending robots where no scientist has gone before: under the ice in Lake Superior during winter.

This week, researchers from the University of Minnesota-Duluth put their first robot in Lake Superior to test it. Think of them as robotic divers... they travel up and down on cables and collect data. The cables will be anchored to the bottom of the lake.

Erik Brown is one of the lead researchers and the acting director of the Large Lakes Observatory at UMD. He says the harsh winters on Lake Superior make it too dangerous for people to go out on ships and collect data.

The city of Ann Arbor recently spent more than one million dollars rebuilding an old mill race along the Huron River. The Argo Cascades is a series of little waterfalls and pools where kayakers and people floating in inner tubes come to cool off.

But downstream from the Cascades on the other side of the river, there’s a problem.

There's been pollution lurking underground for some time from an old industrial plant, and two years ago regulators found that some of the pollution was making its way into the Huron River.

Scientists are analyzing new data that’ll determine whether offshore wind farms are viable in Lake Michigan and the data is more detailed than any available from the Great Lakes so far.

A floating eight-ton research buoy is collecting the data. There are only three such vessels in the world and this is the first one launched in the United States.

The buoy has been anchored about 37 miles off shore for about two months now. Recently crews retrieved the first set of data cards – with information about wind conditions and any bats and birds that fly by. Scientists are now analyzing that data.

Arn Boezaart heads the Michigan Alternative and Renewable Energy Center that’s operating the buoy. "I think we are getting data at this point that will be very useful and will validate the fact that the wind conditions at mid-lake are very promising for potential future use as a commercially viable wind source," Boezaart says.

But right now there is no clear path to proposing an offshore wind farm in the Great Lakes inside the Michigan border.

Of all the land in Michigan, the state owns a little less than 7 and a half percent. That’s about four and a half million acres. And, some people think that’s too much. Some people think it’s not enough. Regardless, every few years, there’s a new call to take a look at how much land is owned by the state, and how it’s being used.

Governor Snyder signed a law recently that limits how much land the state can acquire while the state Department of Natural Resources conducts a study of what the state has and how it’s used.

“The state itself owns millions of acres of land, let alone cooperating with the private sector and there’s no cohesive strategy on how we manage our resources for both terrestrial things like – land-based things, but also aquatic. So one of the things I’d like to see in the special message is setting the framework of how we’re going to evolve over the next few years to have comprehensive strategy for how we’re going to manage land and aquatic resources in the state of Michigan," the Governor said recently.

A news investigation found two natural gas companies might have colluded when bidding on drilling rights in Michigan. Reuters obtained e-mails exchanged between officials from Chesapeake Energy Corp. and Encana Corp. The paper says the e-mails show "that top executives of the two rivals plotted in 2010 to avoid bidding against each other in a state auction and in at least nine prospective deals with private land owners." State lawmakers are pushing for resolution with an investigation.

If you're planning a trip to Michigan's state parks this summer, expect some company.

The parks are on track to break attendance records this year, with more than 25 million visits expected.

It’s mostly thanks to hot weather, lowers gas prices, and cheaper park passes, says Harold Herta of the Department of Natural Resources. "We've seen a lot of people coming out to the parks this year that said, I haven't been to a state park in years, and I thought I'd try it out. Especially in the metro-Detroit area."

The U.S. Coast Guard issued a press release this morning saying all the fuel valves and vents connected to the fuel tank on the sunken barge, the Arthur J, have been plugged.

Crews continue to work on salvaging the 110-foot dredge barge and 38-foot tug that sank yesterday morning one mile off the coast of Lakeport, Michigan.

From their release:

The Arthur J has ten vents to its fuel tank and responders where able to plug four of them early Thursday afternoon, but six remained open until responders were able to plug them late Thursday night.

The impact to the shoreline has been minimal; however there is visible sheening along the shores of Lakeport, but there has been no report of a thick product wash ashore. However, there is still a strong diesel odor in the air, so residents and visitors of the lower Lake Huron area are encouraged to avoid areas where there is an odor in the air. Those who live in the area should remain inside with doors and windows closed as much as possible.

The Coast Guard says the Michigan State Health Department has closed beaches from the Blue Water Bridge north to Lakeport State Park.

The diesel fuel that did spill remains on the lake. No wildlife impacts have been reported yet. The Coast Guard says "weather and lake conditions are not optimal for product clean up, but the clean-up efforts continue vigilantly."

The sunken dredge barge and tug were owned and operated by MCM Marine.

Early reports indicated the barge and tug began taking on water around 4 a.m. yesterday. The Coast Guard reports the cause of the accident at this time is still unknown.

The U.S. Coast Guard released a statement this morning declaring that the diesel fuel tanks onboard the sunken dredge, the Arthur J, have been secured and that no more diesel fuel is spilling into Lake Huron:

All the fuel valves and vents on the Arthur J have been plugged.

The Arthur J has ten vents to its fuel tank and responders where able to plug four of them early Thursday afternoon, but six remained open until responders were able to plug them late Thursday night.

The impact to the shoreline has been minimal; however there is visible sheening along the shores of Lakeport, but there has been no report of a thick product wash ashore. However, there is still a strong diesel odor in the air, so residents and visitors of the lower Lake Huron area are encouraged to avoid areas where there is an odor in the air.

Thursday, July 19, 12:26 p.m.

Mlive.com reports that if storms do not let up, all 1,500 gallons of diesel fuel will get into Lake Huron.

The Michigan Department of Enviromental Quality is monitoring the situation from the periphery, and spokesman Brad Wurfel said ongoing storms may limit the effectiveness of the containment boom.

"We're hoping to recover all we can," he said. "But it's anticipated that if the storms do not let up, it's best to plan on the idea that all 1,500 gallons will get into the lake."

The weather, the weight of the fuel, wind direction and underwater currents make it difficult to predict where the fuel may head. Some local beaches may see a sheen, Wurfel said, but the "environmental impact is not expected to be catastrophic."

"The upside is, it's a big lake. A lot of this will dissipate."

St. Clair County officials have closed all public beaches on Lake Huron as a precautionary measure, according to health education and planning director Jennifer Michalul.

A local hazmat team and fire crew are aiding the Coast Guard, which has established 100-yard safety zone around the periphery of the oil sheen.

When was the last time you were someplace so dark that you could look up at the night sky and actually see the stars? Not just a handful, but hundreds or thousands?

“The Milky Way when it rises here looks like a thunderstorm coming toward you. And you think, oh my god, it’s going to cloud over and it’s not, it’s the Milky Way rising, it’s the edge of our galaxy coming up.”

That’s a scene from a new documentary. It’s called The City Dark and it airs on PBS stations starting tonight (check your local listings).

The film takes a look at our love affair with artificial light – and why humans and wildlife need the night sky. Ian Cheney directed and produced The City Dark and we spoke with him for today's Environment Report. Cheney grew up in rural Maine but has been working in New York City. I asked him why he wanted to make this film.

Ian Cheney: Well, when I moved to New York City, one of the first things I realized was that I was missing the night sky, and that launched me on a journey to explore this broader topic of light pollution and how artificial light affects our world.

Scientists know a lot about how natural places process carbon dioxide. But there hasn’t been a lot of research into what happens throughout the year in the green spaces in cities and suburbs.

Emily Peters is an author of a paper out this week in the Journal of Geophysical Research. She’s been looking at how plants and trees in one suburban neighborhood take in carbon dioxide during the year... and how they offset the carbon dioxide people in the neighborhood emit – by say, driving their cars.

“In the summer we found the uptake of carbon dioxide from the vegetation is enough to offset fossil fuel emissions – just in the summer.”

She says evergreen and leafy trees took in more CO2 during the middle of the summer. Lawns did the best job of taking in CO2 during the spring and fall. But Peters says those plants did NOT balance out the total amount of carbon dioxide released in the suburban neighborhood by burning fossil fuels over the year.

If you're wondering: do certain species of trees do a better job than others?

"That is the question everybody wants answered - we can’t go out with this study and tell city foresters they should plant more of this kind of tree vs. this kind of tree."

For some, the magic of Isle Royale doesn't necessarily reside in the boat trip to the island.

Two days before Rebecca Williams and I left on our reporting trip, a friend and I were having lunch together.

"You're not riding on the 'Barf Barge' are you?!"

"The boat from Copper Harbor?"

"Yeah, I took that trip. We were on Isle Royale for a week. The first half of the week, all we could talk about was the boat trip over. And the second half of the week, all we could talk about was the boat trip back!"

On her trip, as the ship pulled out of Copper Harbor, the captain came on the loudspeaker.

"O.k., folks," the captain started. "We have the forecast for our crossing. And I just want to say... we're all in this together. We can get through this."

The snack bar was not open on that crossing.

But the snack bar was open for our trip.

The seas got a little rough (I saw a few eight footers roll by). And a trip to the restroom wasn't a straight walk to the door. You had to ping-pong yourself from table, to wall, to other passenger (excuse me), to the door.

Emergency cups and plastic grocery bags were deployed by some, but their "green-around-the-gills" condition didn't spread throughout the cabin.

The owners of the Isle Royale Line from Copper Harbor tell me the round-bottomed "Barf Barge" was retired in 2004. Their new boat, the Isle Royale Queen IV, rolls a lot less in heavy seas, and the new boat cut an hour off the trip.

What once took around four hours, now takes around three.

To get a sense of the crossing, I mounted a time lapse camera near the bridge. So here's the 54 mile crossing in less than two minutes.

Cell phones don't work on the island. Senses that can be overwhelmed by a connected, electric lifestyle are freed to look up, and take in the wind, waves, rock, and soil.

What makes the Isle Royale so special? We asked the Isle Royale Line's retired Captain Donald Kilpela that question:

Kilpela first made the trip to Isle Royale in 1945. And he and his family have been running the ferry service in Copper Harbor since 1971. His sons Ben and Don Jr. now run the boat. The family has been crossing Lake Superior to Isle Royale every summer since they started the business.

Two other people who know the island well have spent a good part of their lives here.

Rolf Peterson has been studying the interactions of wolves and moose on Isle Royale for more than 40 years. He and his wife Candy spend around eight months of each year on the island, and they raised their two kids on Isle Royale while living in the tiny Bangsund Cabin.

Isle Royale became a National Park in 1940, and was designated as a wilderness area in 1976. Humans are not in control here. It's an ideal laboratory for Peterson and the other researchers studying wolves and moose here.

Much of what scientists around the globe know about wolves and their behavior comes from Michigan's Isle Royale. The research project here is the longest running continuous study of any predator-prey system in the world.

All this week, we'll bring you stories about this research and about the people who make it happen - online and on-air.

Isle Royale is the least visited National Park, but as Captain Kilpela pointed out, it's the most re-visited one.

Many of you have had your own personal experiences with the island. We invite you to share your experiences about Isle Royale in the comment section below. In six words or less - tell us - what's so special about Isle Royale?

The Nature Conservancy has released an analysis saying that invasive species such as zebra mussels and sea lamprey cost businesses and consumers hundreds of millions of dollars each year, besides damaging the environment in the Great Lakes region.

Detroit Regional Chamber of Commerce officials said today they opposed a ballot initiative aimed at creating a new renewable electric energy standard for the state, according to MLive. The state is currently working toward a standard that calls for generating 10 percent of the state's electricity from renewable sources by 2015.

The ballot initiative seeks to bump up that mandate to 25 percent by 2025. From MLive:

Chamber officials said any changes to Michigan’s renewable energy standard should wait until the current standard has been fully evaluated in three years.

“Michigan is already on an intelligent and affordable clean energy path because of the 2008 energy law, which passed the Legislature with overwhelming bipartisan support, said Chamber president and CEO Sandy K. Baruah in a statement.

Last week, during a segment for the Environment Report, James Clift, Policy Director for the Michigan Environmental Council (MEC), said Michigan currently gets around 3.5 percent of its energy from renewable resources.

The MEC supports the ballot initiative. Clift said a new standard would continue the progress made after the 2015 standard is met (adding about 1.5 to 2 percent of renewable energy each year).

"The Michigan Environmental Council commissioned a report last year looking at the nine oldest coal plants in Michigan, said Clift. "That report found that Michigan residents have health care costs and damages of about $1.5 billion a year – just from those nine oldest coal plants. So, transitioning away from coal to clean more renewable energy, we hope will put a significant dent in those health costs that we are currently occurring. "

Utility companies oppose increasing the renewable electric energy standard saying such a standard should not be set by amending the state constitution, which the ballot proposal calls for.

Michigan Radio's Zoe Clark spoke with Brad Williams of the Detroit Chamber of Commerce about the issue:

"We’re looking at this as a protection of the constitution," said Williams. "There are legislators who can serve their full fourteen years in Lansing without having a good grasp of energy policy. And, so, to ask voters to make this decision and embed it into the constitution really isn’t fair to voters."

The loans, which will be administered by banks and agricultural lenders, will meet an estimated total economic need of some $300 million in the state’s fruit growing and processing industry, Creagh said while attending the Michigan Food Processing and Agribusiness Summit.

Securing the loan guarantees at a low interest rate of 1 percent or 2 percent could cost the state about $15 million, Creagh said. The 5-year loans would be structured so borrowers would only pay interest in the first two years, he said.

Enbridge Energy operates the pipeline that ruptured in Marshall almost two years ago. The Environmental Protection Agency says more than one million gallons of thick tar sands oil spilled into the Kalamazoo River. The oil spill is still being cleaned up.

Since the spill, Enbridge has been making repairs on that pipeline. It’s known as Line 6B.

Now, the company plans to replace the entire pipeline from Griffith, Indiana to Marysville, Michigan.

Oil is hovering around $100 a barrel. In 2002, oil was about $20 a barrel.

Natural gas is currently at 2002 prices. In fact, the price of natural gas is half of what it was one year ago.

Why? Because of abundant supplies of natural gas, what the U.S. Energy Information Administration calls “robust inshore production.”

There is a glut of gas.

This increased supply is mostly due to hydraulic fracturing. More importantly, a newer way to use the drilling method, horizontal hydraulic fracturing. Horizontal ‘fracking’ has made it easier and cheaper to extract natural gas from shale deposits in the U.S. and other sites around the globe.

Horizontal fracking has meant a boom in gas drilling and production. It’s meant more jobs in certain areas of the country. It’s meant greater dependence on domestic energy, and less dependence on foreign energy.

Because burning natural gas emits about half of the CO2 emissions of coal or oil, it means less of the greenhouse gases that are causing climate change.

Michigan politicians are beginning to wrestle with an issue that's proven to be contentious in other parts of the country.

"Fracking" or hydraulic fracturing is a controversial method of extracting natural gas by pumping water, sand and chemicals into deep underground wells. Both opponents and advocates of the process have started taking action in the state legislature.

This month, Marathon officials said 86 percent of the owners have chosen to enroll in the buyout program — meaning they are willing to have their home appraised and see a monetary offer from the company.

Marathon is sweetening the pot, too, as it initially set a minimum appraisal price of $40,000 per home but already has bumped that figure up to $50,000.

The buyout plan is expected to head off lawsuits from those who live in this area. So far, the program has avoided legal entanglements, but it has generated plenty of hard feelings.

Oakwood Heights is an area surrounded by heavy industry. In addition to the refinery, there's the city's sewage treatment plant, a salt mine, a steel factory, and other industries.

I drove around with her as we followed trucks laden with liquefied manure and watched as they spread the liquid on nearby farm fields.

It's a practice that can add nutrients back to the land if done right, but with the huge quantities of manure these CAFOs are dealing with year round - doing it right is something they've had trouble with.

And Henning, a "Sierra Club Water Sentinel," has been watching them - reporting them to state officials when they weren't complying with the law.

It's clear from visiting these communities that these large scale farms have caused rifts among neighbors; some like the income they make selling corn and renting land to CAFO operators, but others feel CAFOs threaten their health and the beauty of rural farming life.

Working as an environmental activist in rural Michigan (she formed the group Environmentally Concerned Citizens of South Central Michigan), Henning says she's felt those divisions first-hand - saying she's been harassed and threatened on numerous occasions.

Family farmer and activist Lynn Henning exposed the egregious polluting practices of livestock factory farms in rural Michigan, gaining the attention of the federal EPA and prompting state regulators to issue hundreds of citations for water quality violations.

She's also been to the White House to meet President Obama. And now, here she is on Bill Maher. To watch, we have to pull up a chair up to "imnewshound's" television - he has subscription to HBO, after all (and being HBO and Bill Maher, be warned - there is some foul language):

A new law will soon limit the types of waste that can be thrown into pits and barrels to be burned. Plastics, chemically treated wood, and electronics are among the types of trash that cannot be burned.

The new rules don’t go as far as some people wanted, which was to ban outdoor burning altogether.

There were fights between neighbors about drifting smoke -- in some cases, causing or aggravating asthma attacks.

But burning waste is so common in parts of rural Michigan that a compromise was struck. Some of the most toxic materials are banned, but grass, leaves and other yard waste can still be burned.

The director of the state Department of Environmental Quality Dan Wyant said he hopes this is the beginning of a culture change in rural Michigan.

“We’ll go out, and we’re trying to educate,” said Wyant. “We’re not trying to be heavy-handed in our enforcement, but we will communicate about the law, and we do want to move away from outdoor burning.”

The trends are part of a broader decline in worry about environmental threats documented in the poll.

Gallup asked Americans to say how much they worry about each of seven environmental problems. All show significantly less worry today than in 2000, when worry was at or near its high point for each item. The declines in concern about drinking-water pollution and air pollution are the largest for the problems included in this year's poll.

Here's a breakdown of those concerned "a great deal" about the following problems:

Pollution of drinking water

2000 - 72 percent

2012 - 48 percent

Air pollution

2000 - 59 percent

2012 - 36 percent

Pollution of rivers, lakes, and reservoirs

2000 - 66 percent

2012 - 48 percent

Contamination of soil and water by toxic waste

2000 - 64 percent

2012 - 50 percent

The loss of tropical rain forests

2000 - 51 percent

2012 - 37 percent

Global warming

2000 - 40 percent

2012 - 30 percent

Extinction of plant and animal species

2000 - 45 percent

2012 - 36 percent

Thoughts? Is this a sign of a perceived improvement in environmental conditions? A shift in perception because a Democrat occupies the White House vs. a Republican? Or another sign of hard economic times as more people shift their worries to just making a living?